2.0 Analysis 2.1 General The following analysis concentrates on the emergency response, the control of the fire, the evacuation, and the origin of the fire. 2.2 Emergency Response The ERS responded within three minutes, as required, following the activation of the crash bell by the control tower supervisor. Although the fire had already been extinguished by the cabin and flight crew, the ERS personnel removed the contents of the overhead stowage bin and further saturated it with extinguishing agents. They also assisted in the evacuation by steadying the escape slide, slowing the descent of the passengers, and rounding up some of the passengers who had wandered onto the grass area. The intervention of the Dorval firemen, the MUCPD and Urgences-Sant was delayed by the use of the 911 services, whose operator did not comprehend the nature of the emergency. Fortunately, this time, their intervention was not paramount to the success of the emergency response. 2.3 Control of the Fire Two flight attendants initially responded to the presence of the smoke in the aft cabin. While they gathered fire-fighting equipment, the second officer opened the aft stairway to give a direct access route to the firemen. Following his departure towards the cockpit, flames which were not formerly visible emanated from the bin. The flight attendant then discharged a Halon fire extinguisher over the bin door. The air moving into the aircraft from the aft stairway probably activated the fire and moved the smoke towards the front of the cabin. This, in turn, motivated the passengers to leave their seats and move towards the front of the cabin. The second officer and the ERS personnel further saturated the contents of the bin, thus minimizing the quantity of smoke and reducing the level of damage to the aircraft. 2.4 The Evacuation The evacuation was started approximately 2 1/2 minutes after the smoke was initially noticed by the flight attendants. Within the next 90 seconds, all persons on board had evacuated the aircraft using only one exit/escape slide. Only the first officer used another exit, his right side window. The three aft exits were unusable due to their proximity to the fire and smoke. The four overwing exits were unsuitable for egress because of the rapid displacement of the smoke to this area and the movement of the passengers to the front of the aircraft. This left the two front doors as usable exits. The left front door was used successfully. The right exit could have been used only after removing the hand baggage which was piled up against it. Since no able bodies were positioned, or requested, at the bottom of the escape slide until the arrival of the ERS personnel, the first passengers to evacuate landed hard on the concrete ramp. Several of those passengers suffered back and lower body soreness in the days following the incident. Many passengers were disoriented upon exiting the aircraft. It was dark, rainy, and windy, and they were not familiar with the configuration of the airport. Until guidance was available, some passengers, in an attempt to move away rapidly from the aircraft, ventured towards the grass area, close to runway 10/28 and taxiway Echo where there was aircraft movement. Fortunately, the evacuation of the aircraft involved only 60 passengers, and all used the same exit. Therefore, controlling and directing those 60 passengers while close to a terminal building was easily manageable and was rapidly under control. 2.5 Origin of the Fire An extensive study of the overhead stowage bin and its contents clearly demonstrated that the source of ignition was outside the flight attendant's bag and was not an aircraft system. The 100 per cent polyester blankets were the source of fuel for the fire. The TSB Engineering Branch study showed that the blankets could sustain a fire and that a match similar to the ones found in the aft lavatories could be a source of ignition. Evidence indicates that the fire was not accidental. Circumstantial evidence such as the matches, which had been lit, found in the handtowel dispensers of the aft lavatories close to seat row 28, combined with the fact that a similar match could have been the source of ignition, and pertinent passenger statements, have prompted a separate investigation by the Arson Squad of the Montreal Urban Community Police Department to determine the source of ignition. 3.0 Conclusions 3.1 Findings The flight and cabin crew was certified and qualified in accordance with existing regulations. The aircraft was certified, equipped, and maintained in accordance with existing regulations and approved procedures. The ERS and RCMP personnel successfully responded and controlled the emergency situation; the other emergency respondents were delayed by the lack of information and understanding of the occurrence by the 911 operator. Only one exit was used and required to evacuate all the passengers. Some passengers sustained minor injuries during the evacuation. No able bodies were requested to steady the bottom of the escape slide during the initial portion of the evacuation. During and immediately following the evacuation, some passengers were reported wandering around taxiway Echo and runway 10/28, and had to be re-directed to the terminal. The crew's response to the fire minimized damage to the aircraft. The fire was contained within the overhead stowage bin. The fuel source for the fire was polyester blankets. No aircraft system acted as the ignition source of the fire. Despite meeting the FAR flammability standards for cabin interior materials, the NWA passenger service blanket material supported fire when folded flat. 3.2 Causes A fire developed in an overhead stowage bin during push-back. The cause of the fire could not be determined. All evidence indicates that the fire was not accidental. 4.0 Safety Action 4.1 Action Taken 4.1.1 Joint Pilot/Cabin Crew Emergency Training Northwest Airlines has indicated that, beginning in January 1995, joint training for pilots and flight attendants will be conducted during annual recurrent training. The training will focus on communications between the flight deck and cabin, and will include in-flight fire scenarios. 4.1.2 911 Communications During Airport Emergency Responses Subsequent to this occurrence, the Centre d'Urgence established a new method of operation. Specifically, 911 operators have received directions on the amount and type of information to be collected prior to initiating emergency responses to local airports. 4.1.3 Unilingual Evacuation Instructions Although not required by regulation, most Canadian air carriers endeavour to provide safety briefings in both official languages. Also, some foreign carriers routinely ensure that bilingual flight attendants are on aircraft serving Quebec airports to provide bilingual safety briefings during these flights. In July 1994, the TSB forwarded an Aviation Safety Advisory to Transport Canada (TC) highlighting the potential for delayed and/or adverse reactions to unilingual emergency instructions by passengers who do not comprehend the language of instruction. In its response, TC indicated that, with the rewriting of the Canadian Aviation Regulations, safety briefings in both official languages will become a requirement under specified circumstances. Also, since the International Civil Aviation Organization (ICAO) has no established standard regarding the language of safety announcements, TC will address this issue with ICAO. 4.2 Action Required 4.2.1 Passenger Service Blanket Flammability Passenger service blankets are carried on most large air carrier aircraft and are usually stored in the overhead bins in the cabin. In addition to using the blankets for passenger comfort, several Canadian air carrier Flight Attendant Manuals instruct flight attendants to use the blankets for smothering flames on a person's clothing or seat. As demonstrated by this incident and in TSB tests, some passenger service blankets have adverse flammability characteristics even though the blanket material passed the flammability test prescribed for cabin interior materials. In May 1994, the TSB forwarded an Aviation Safety Advisory to TC and the Cabin Safety Standards section of the FAA indicating that passenger service blankets should meet an appropriate flammability standard and that TC might wish to advise Canadian air carriers that passenger service blankets may present a fire hazard. In July 1994, using TSB information from this occurrence, the National Transportation Safety Board (NTSB) recommended that the FAA develop a fire performance test method and performance criteria (standard) for blankets supplied to commercial operators, then require those operators to use only those blankets that meet the standard (NTSB-A-94-131). At the same time, the NTSB also recommended that the Air Transport Association of America (ATA) warn association members about the flammability of blankets used for passenger comfort and urge members to replace these blankets with blankets containing more fire-resistant materials (NTSB-A-94-132). In August 1994, the ATA response to the NTSB recommendation indicated that ATA had advised its members about the flammability of passenger service blankets. In January 1995, in response to the TSB Advisory, TC indicated that they would be reviewing the issue of blanket and pillow flammability with the FAA via an international working group and that it would be premature to advise carriers of the potential fire hazard prior to the completion of the working group's activities. The Board understands that the international working group is considering issues such as types of fabric and flammability protection processes, effects of in-service use, and appropriateness of flammability standards. It is recognized that it may not be practical to disseminate information on these issues until discussed by the working group. However, considering how easily the folded blankets ignited and developed a molten polyester pool fire in both the occurrence and post-incident test, Canadian air carriers may wish to take interim measures based on their assessment of the hazard. Therefore, the Board recommends that: The Department of Transport immediately advise Canadian air carriers about the potential flammability of some passenger service blankets.